The High Throughput Screening Shared Resource allows members of the Cancer Center to use the techniques of high-throughput screening (HTS) of compounds or genomic siRNA libraries. The HTS laboratory provides target assessment and assay evaluation, assay development and testing, screening of chemical compounds or siRNA libraries, data analysis and storage, and hit validation. To gain access to the HTS facility, Cancer Center members must have a project evaluated by the Cancer Center HTS Oversight Committee, which will assess both the practicality and the scientific and therapeutic value of targets for screening. For approved projects, the HTS staff will then assess the cost and practicality of the proposed assay and work with the initiating laboratory to develop the assay into a form suitable for HTS that reproducibly achieves the desired signal to noise statistics. The HTS laboratory works to minimize the cost of the experiment, which often requires changing reagents and sometimes completely redesigning the assay. Once an assay has an acceptable signal to noise ratio in small scale experiments, for compound screens multiple assay plates are treated with DMSO (the compound diluent) to determine reproducibility under conditions similar to HTS screening and then are screened against a test compound library to determine the hit rate. Genomic siRNA experiments are developed in a similar manner, except that they are run in 96 well format in replicate plates and no test library is used before the genomic screen is begun. Just as with compounds, siRNA experimental controls must achieve a reproducible signal to background ratio in runs of multiple plates before the project is allowed to screen the genomic library.